1. Field of the Invention
The present invention relates to a structure for mounting a cable reel and turn indicator switches onto a steering shaft in automobiles. The structure of the invention allows, inter alia, to obviate the need for equipment hitherto considered essential. It therefore simplifies the construction of automobiles fittings and improves fitting process efficiency. In this technical field, the turn indicator switches are also known as winker- or blinker-lighting switches.
2. Description of Background Information
FIGS. 1 to 3 show a known structure for mounting a cable reel and turn indicator switches onto a steering shaft. Such a steering shaft 1 includes an outer tube (tubular ring) 1a at the end where the steering wheel is fitted. An edge of the tubular ring 1a is bonded to three or four stays 2 by welding. These stays 2 are arranged at a given interval in the circumferential direction. The switch body 3 is then fixed onto the stays 2 by first bolts 4. The diametrically opposing sides of the switch body 3 are then provided with a corresponding lighting switch holder 3a or 3b, into which a turn indicator switch 5A or 5B is laterally inserted. The corresponding lighting switch holder 3a or 3b and turn indicator switch 5A or 5B are then clamped by second bolts 6. Further, the upper side (as shown in FIG. 1) of the switch body 3 includes three or four projecting cable reel holders 3c which are arranged at a given interval in the circumferential direction of the switch body 3. The cable reel 7 includes corresponding holder portions 8a extending horizontally from the base of its fixed element 8. Subsequently, the holder portions 8a are clamped onto the cable reel holders 3c by third bolts 9.
In the prior art techniques mentioned above, a switch body 3 is first fixed on stays 2 projecting from a steering shaft 1 by means of first bolts. The turn indicator switches 5A and 5B are then fixed to the switch body 3 by second bolts, while a cable reel 7 is fixed to the switch body 3 by third bolts. In such a construction, bolt-fixing sites amount to about ten, and may downgrade the precision in their mutual positioning.
Moreover, such a structure must employ a number of bolts, e.g., for fixing the switch body 3. It also calls for many fittings or fixtures, adding to material costs. Furthermore, the high number of bolts increases the number of screwing steps, further raising production costs.
In view of the above, a main object of the invention is to provide a fitting structure in which the number of fittings and bolt-fixing sites is reduced, so that productivity of car parts assemblies is improved, and production costs are reduced.